19 replies to this topic

[Cook]

Hi all.  Thought I would just continue on here to save some continuity.  I have a newly built gauge cluster from a reliable source, with a temp sensor supplied by same person, so I would like to think that they are compatible and rule that out. The wiring has only recently been completed. All the gauges on the cluster work save for the tacko (not yet connected up) and the temp gauge which is the problem.  It was suggested that to check if the issue was the sensor by putting ignition in the on position and earth out the wire on the block and see if the gauge moves.  Now I have read that this is not ideal and could harm the gauge which is the last thing I want to do.  Would it be reasonable to try this method at all? I do have a multimeter so was wondering if I can possibly identify the issue using this.   Thanks in advance. Cheers Ron

[hanra]

Measure from the body of the Temp sensor to Neg on your battery. How many ohms do you have? 

[Cook]

Thanks Brad for the response. Unfortunately that is going to be a bit difficult as battery is in the hatch area. Cheers Ron

[hanra]

Well just measure to the chassis of the body. 

[Cook]

Ok cool.  Will get back to you once I have had a chance to do so. Cheers Ron

[Cook]

Hi Brad.  Not sure if I did it right. Multimeter read 1 when switched to ohms and read the same when placed on sensor with neg on chassis rail.  Cheers Ron

[Rockoz]

Turn your meter to ohms.

Short the leads. That will give you a reading for a short circuit.

Check between the chassis and the block.

That should read the same as the previous 2 readings, or very close to it.

Then check between the block and the outer section of the temp sender.

Again it should be close to the short circuit reading.

Thread tape and sealers can prevent the body of the sender from earthing properly.

 

Although not generally recommended, a quick short of the sender wire to a good earth shouldnt be a problem.

One person on the wire, one person watching.

Will see something happen in a fraction of a second.

 

Cheers

 

Rob

[hanra]

Yep, thats where I was heading. I wanted you to confirm that the body of the sender was getting a good earth via the block to chassis to battery. 

 

As above regarding the shorting of the sender wire. Yep, just be quick, have someone watching and you wont hurt anything. 

[Cook]

Hi all. Just an update.  I got another auto elec out (that's another story) to look at it and few other matters and when he shorted it out the needle hardly moved.  After trying a number of things he said he believed the issue seems to be with the gauge.  FWIW the gauge cluster was rebuilt with Autometer gauges and the readings for the sensor in this case are: at 120deg. 1120 and at 250 deg 65. Somewhat different to original gauge settings as I am told.  I also have an issue with the fuel gauge showing 1/2 way when the tank is full.  Cluster going back to the person who built it to see what he can determine.  With mail times along the eastern seaboard blowing out I might have it back by Christmas lol.  Challenge will be if we are out of lockdown by then. Cheers Ron

[73SUNBURSTEXYOUWON]

Does/has the dash cluster also need to have its own earth to work effectively.

[Cook]

Hi Jaso, I believe the earth is run through the main clip to the cluster, if I heard right from the auto elec. Cheers Ron

[VDO]

The Autometer gauges are a different ohms spec to the original VDO ones.  All your gauges are 73-10 ohms range from the factory.  The tech should have supplied you with matching senders, but the fuel sender will have to stay original to the tank.  If you're getting half tank reading when tank is full, that's probably because the Autometer fuel gauge is most commonly10-180 ohms range and the fuel sender is 73-10 ohms, which would place the wrong reading as you're finding.  I don't think Autometer make a gauge with 73-10 ohms range. You need to ask the gauge guy the ohms range of the other two gauges, so you can fit matching senders.  A solution for the mis-match in the fuel gauge would be an interface, which will make the gauge and sender line up.  Ebay has them, or the gauge guy should also have them.  Same issue with the temp gauge, when you short it out you deliver zero (0) ohms to the gauge, which will hardly show on a 10-180 ohms temp gauge range. 

[Cook]

Hi Chris and thanks for the explanations.  Just to explain a bit more, the guy who restores and builds clusters does a lot of old cars and a heap of Toranas so I assume he has a pretty good knowledge of what should be.  He did provide the sender for the temp gauge and that is what I am using.  The fuel gauge is as you say, original to the tank, which I told him at the time, so again I can only assume he matched that up but, if Autometer don't produce a gauge to match then I'd be surprised if there weren't more people with issues coming out of his work.  I am interested about the interface option. I asked my auto elec if there was such a thing to "regulate" if that's the right word but he wasn't confident.  The gauge should be in NSW early next week and we will see what transpires.  Thanks again.  Cheers Ron

[VDO]

https://www.ebay.com...353.m1438.l2649

[VDO]

Also, I stand corrected.  Autometer do make gauges with 73-10 ohms range.

 

I restore many many gauges every day, but I don't tend to use Autometer, for reasons better kept to myself.

 

Maybe been doing this too long... 45 years.

[Cook]

Thanks again Chris.  Will certainly keep the ohms converter module in mind. Cheers Ron

[Cook]

Hi all. Finally got the cluster back from NSW. Took 3 weeks via Auspost.  The builder, bench tested it all and said he couldn't find any faults with it. I plugged it in and in the "on" position all gauges move. So one stp forward. Problem is, when I screw it into the dash the temp gauge doesn't move. I think slight pressure on the wires when mounting it is causing this misconnect, presumably at the main clip.  So if I am able to get the multimeter on the pin in the main clip and wiggle the wires around hopefully that will show a drop in resistance.  Bearing in mind I have limited knowledge, does that sound feasible.  Cheers Ron